Fan assembly

Abstract

A fan assembly for creating an air current includes a base having an air inlet and an air outlet, the base housing an impeller and a motor for rotating the impeller to create an air flow passing from the air inlet to the air outlet. The fan assembly further includes a vertically oriented, elongate annular nozzle including an interior passage having an air inlet for receiving the air flow from the base and a mouth for emitting the air flow, the nozzle defining an opening through which air from outside the fan assembly is drawn by the air flow emitted from the mouth.

Description

REFERENCE TO RELATED APPLICATIONS[0001]This application claims the priority of United Kingdom Application Nos. 0903667.4, 0903675.7 and 0903666.6 filed 4 Mar. 2009, the entire contents of which are incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention relates to a fan assembly. In a preferred embodiment, the present invention relates to a domestic fan, such as a tower fan, for creating an air current, for example in a room, office or other domestic environment.BACKGROUND OF THE INVENTION[0003]A conventional domestic fan typically includes a set of blades or vanes mounted for rotation about an axis, and drive apparatus for rotating the set of blades to generate an air flow. The movement and circulation of the air flow creates a ‘wind chill’ or breeze and, as a result, the user experiences a cooling effect as heat is dissipated through convection and evaporation.[0004]Such fans are available in a variety of sizes and shapes. For example, a ceiling fan can ...

AI Technical Summary

Benefits of technology

[0014]The nozzle may comprise a plurality of spacers for urging apart the overlapping portions of the inner casing section and the outer casing section of the nozzle. This can enable a substantially uniform outlet width to be achieved about the opening. The uniformity of the outlet width results in a relatively smooth, substantially even output of air from the nozzle.

[0015]The nozzle may comprise a surface, preferably a Coanda surface, located adjacent the mouth and over which the mouth is arranged to direct the air flow emitted therefrom. In the preferred embodiment, the external surface of the inner casing section of the nozzle is shaped to define the Coanda surface. A Coanda surface is a known type of surface over which fluid flow exiting an output orifice close to the surface exhibits the Coanda effect. The fluid tends to flow over the surface closely, almost ‘clinging to’ or ‘hugging’ the surface. The Coanda effect is already a proven, well documented method of entrainment in which a primary air flow is directed over a Coanda surface. A description of the features of a Coanda surface, and the effect of fluid flow over a Coanda surface, can be found in articles such as Reba, Scientific American, Volume 214, June 1966 pages 84 to 92. Through use of a Coanda surface, an increased amount of air from outside the fan assembly is drawn through the opening by the air emitted from the mouth.

[0016]In the preferred embodiment an air flow is created through the nozzle of the fan assembly. In the following description this air flow will be referred to as primary air flow. The primary air flow is emitted from the mouth of the nozzle and preferably passes over a Coanda surface. The primary air flow entrains air surrounding the mouth of the nozzle, which acts as an air amplifier to supply both the primary air flow and the entrained air to the user. The entrained air will be referred to here as a se

Problems solved by technology

A disadvantage of this type of arrangement is that the air flow produced by the rotating blades of the fan is generally not uniform.

These variations result in the generation of an uneven or ‘choppy’ air flow which can be felt as a series of pulses of air and which can be uncomfortable for a user.

It is undes

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